I have recently added a socket to my Coco 3 and have two 6309's that aren't working. I checked connections from the top of the CPU to both cartridge port and GIME chip, all are fine. Both 6309's show a nearly blank screen with a dozen gray vertical lines. I also have two 68A09E's that I tried. Both work fine (at least I get a proper boot screen). Do I have bad 6309's then?